Styjun

i'm developing a chat application, for message notification i'm using firebase push notifications and for call alert also. But i searched and learn about Push Kit voip notifications for call alerts while app is in background and kill state. I have enable the voip services and from Xcode capabilities and added code for Push Kit and its delegates. Now when i run the app i revcieve a push token from this delegate,

func pushRegistry(_ registry: PKPushRegistry, didUpdate pushCredentials: PKPushCredentials, for type: PKPushType)
let token = pushCredentials.token.map String(format: "%02.2hhx", $0) .joined()
NSLog("voip token: (token)")
UserDefaults.standard.set(token, forKey: Key_Push_token)
UserDefaults.standard.synchronize()


I pass this token to my server side and store it, now as before my server send me firebase push notification , my server side send that firebase notification on this push token, but i'm not receiving notifications when app is in background or kill state. I'm again receiving firebase notification instead of Voip Notifications. This is my code,

let mainQueue = DispatchQueue.main
 let voipRegistry: PKPushRegistry = PKPushRegistry(queue: mainQueue)
 voipRegistry.delegate = self
 voipRegistry.desiredPushTypes = [PKPushType.voIP]

extension AppDelegate: PKPushRegistryDelegate 
func pushRegistry(_ registry: PKPushRegistry, didUpdate pushCredentials: PKPushCredentials, for type: PKPushType) 
 let token = pushCredentials.token.map String(format: "%02.2hhx", $0) .joined()
 NSLog("voip token: (token)")
 UserDefaults.standard.set(token, forKey: Key_Push_token)
 UserDefaults.standard.synchronize()



func pushRegistry(registry: PKPushRegistry!, didUpdatePushCredentials credentials: PKPushCredentials!, forType type: String!) 

 //print out the VoIP token. We will use this to test the notification.
 let token = credentials.token.map String(format: "%02.2hhx", $0) .joined()
 NSLog("voip token: (token)")


private func pushRegistry(registry: PKPushRegistry!, didReceiveIncomingPushWithPayload payload: PKPushPayload!, forType type: String!) 

 userInfo = payload.dictionaryPayload["aps"] as? [AnyHashable:Any]

 print(userInfo!)
 let payloadDict = payload.dictionaryPayload["aps"] as? Dictionary<String, String>
 let message = payloadDict?["alert"]
 print(message!)

 //present a local notifcation to visually see when we are recieving a VoIP Notification
 if UIApplication.shared.applicationState == UIApplicationState.background 
 print("Background")
 

 else 

 

 NSLog("incoming voip notfication: (payload.dictionaryPayload)")


private func pushRegistry(registry: PKPushRegistry!, didInvalidatePushTokenForType type: String!) 

 NSLog("token invalidated")

How i can get voip notification when app is in background state. What is difference between firebase notification and voip notification?